The invention resides in a drive shaft with an outer tube extending from one end of the driveshaft and a core shaft which extends from the other end and is at least partially inserted into the outer tube of the drive shaft and with an elastomer damping element which is disposed between the outer tube and the core shaft and is vulcanized to the inner surface of the outer tube and to the outer surface of the core shaft.
Motor vehicles include drive lines with drive shafts for the transmission of the drive torque from the engine or the transmission to the rear axle differential of the motor vehicle. For damping torsion vibrations in the drive line usually damping elements are provided in the drive shaft, which consist of an elastomer damping material.
DE 101 51 714 A1 discloses a driveshaft which comprises an outer tube connected to one end of the shaft and a core shaft inserted at least partially into the outer tube and connected to the other end of the shaft and an elastomer damping element. The elastomer damping element is disposed between the outer tube and the core shaft and is vulcanized to the inside of the outer tube and also to the outside of the core shaft.
DE 922 502 further discloses a driveshaft which also comprises a hollow shaft and a core shaft disposed in the hollow shaft and an elastic element, which is disposed between the two shafts and which may consist for example of rubber. The elastic element may be vulcanized between the two shafts. It is furthermore indicated that, for increasing the bending resistance of the shaft, the elastic elements of rubber may be provided with annular metal inserts which however are not described in details.
Another drive shaft wherein a core shaft is inserted into an outer tube and an elastomer damping element is provided between the two is described in GB 459 105.
Finally, DAS 1 044 637 discloses a drive shaft wherein a core shaft is centrally disposed over its full length in a hollow shaft. Between the outside of the hollow shaft and a sleeve which extends around the hollow shaft and is connected to the core shaft at its insertion end, an elastic damping element is provided which is connected on one hand with the hollow shaft and on the other hand with the sleeve. By centering the core shaft in the hollow shaft bending vibrations are said to be prevented.
It is the object of the present invention to provide a drive shaft which includes a damping element for damping torsional vibrations and which is insensitive to bending vibrations and to a method manufacturing such a drive shaft.